1. Field of the Invention
The present invention relates to an electronic file equipment. More particularly, it relates to an electronic file equipment adapted to access image data at high speed.
2. Description of the Related Art
An electronic file equipment for electronically stocking image information has been known from, for example, the disclosure of the official gazette of Japanese Patent Application Laid-open No. 186362/1987.
In such a prior-art electronic file equipment, the image information items are recorded in an optical disk. Besides, a recording medium which stores management information for managing the image information recorded in the optical disk is disposed separately from this optical disk, thereby to decrease the time needed for retrieval.
Especially in case of stocking a large quantity of image information, the image information items are recorded in an optical disk library. The optical disk library is a device in which a plurality of optical disks are housed, and in which the optical disk can be mounted on a disk drive as need be so as to be accessed. In this case, it is common to further dispose a magnetic disk device which stores management information for managing the images recorded in the optical disks housed in the optical disk library.
In the case of using the optical disk library, the large quantity of image information can be stocked. In this case, however, time periods for mounting the optical disk on the disk drive and removing it therefrom are necessitated. Accordingly, the image information cannot be accessed at high speed.
Moreover, with the prior art stated above, when the optical disk becomes damaged, by way of example, the image information items recorded in this optical disk are lost, and they cannot be recovered. That is, the prior-art equipment is not always very highly reliable.